1. Field of the Invention
This invention relates to biopsy sampling.
2. Description of Related Art
There are many biopsy procedures in which tissue samples are taken for later histology. In xe2x80x9ccoldxe2x80x9d biopsy procedures, surgical forceps are inserted within, for example, an endoscope, and are used to resect (i.e., cut) a tissue sample from, for instance, the biliary tree or colon. The forceps, and, hence, the tissue sample, are then removed from the patient through the endoscope.
Extensive bleeding can occur as a result of cold resecting, which can lead to dangerous blood loss levels. Hence, after the tissue sample is removed, another device can be inserted into the patient through the endoscope to stop the bleeding. These devices include tamponade devices which apply pressure to the bleeding site to stop the bleeding, devices which apply alcohol to the bleeding site to stop the bleeding, and electro-cautery devices which apply radio frequency (RF) energy to one or more electrodes (monopolar or bipolar) in contact with the bleeding site to cauterize the tissue and stop the bleeding. Following resecting, time is required to remove the forceps and tissue sample and insert a device to stop the bleeding. During this time, the resecting site continues to bleed.
Alternatively, a xe2x80x9chotxe2x80x9d biopsy procedure is performed using surgical forceps in which the jaws are electrodes (bipolar or monopolar). After the tissue sample is resected, the forceps are brought in contact with tissue remaining at the resecting site and RF energy is applied to the forceps to cause current to flow (i.e., cauterization) through the resecting site tissue to coagulate the tissue and stop the bleeding. Coagulation of the tissue may also kill cancerous or precancerous tissue at the resecting site. Often, RF energy is applied to the forceps during resecting to help cut the tissue sample as well.
The tissue sample is again removed from the patient through the endoscope for histology. The tissue sample, however, may be inadvertently cauterized when the resecting site is cauterized rendering the tissue sample unusable for histology, e.g., the question of cell malignancy cannot be answered. The forceps may be lined with insulating material to electrically isolate the tissue sample from the forceps. However, heat generated when the resecting site tissue is cauterized may coagulate the tissue sample within the forceps, again, rendering the tissue sample unusable for histology.
U.S. Pat. No. 5,336,222 to Durgin, Jr. et al., issued on Aug. 9, 1994 entitled Integrated Catheter For Diverse In Situ Tissue Therapy; U.S. Pat. No. 5,403,311 to Abele et al., issued Apr. 4, 1995 entitled Electro-Coagulation And Ablation And Other Electrotherapeutic Treatments Of Body Tissue, and U.S. Pat. No. 5,522,815, issued Jun. 4, 1996 to Durgin, Jr., et al. and entitled Integrated Catheter For Diverse In Situ Tissue Therapy are assigned to the assignee of the present application and are hereby incorporated herein in their entirety by reference.
In one aspect, the invention features an assembly for taking a biopsy sample from a site within the body of a patient. The assembly includes a resecting device having a cutter near its distal end for resecting and containing a tissue sample and a sheath exterior to the resecting device and sized to be present within the body with the resecting device. The sheath includes an electrode element electrically isolated from the resecting device and disposed on the sheath""s outer surface for cauterizing tissue. The resecting device and the sheath cooperate to permit sequential resecting of a tissue sample from a resecting site and cauterizing of the site with the cutter sufficiently spaced from the electrode element to avoid heat damage to the tissue sample.
Implementations of the invention may include the following features. The sheath may include a lumen sized to slidably receive the resecting device or the sheath and the resecting device may be constructed as a unitary device where the cutter extends distally of the termination of the sheath and the electrode is spaced proximally of the cutter. The cutter may include forceps. The electrode element may be a monopolar electrode or a pair of bipolar electrodes, and, in both cases, the electrodes may be cylindrical. The bipolar electrodes may also be xe2x80x9cCxe2x80x9d shaped. Additionally, the sheath may be precurved or the sheath may be deflectable through the use of a tension wire having a distal end fixed toward the distal end of the sheath such that pulling on a proximal end of the tension wire causes a distal portion of the sheath to bend. The sheath may include a lumen disposed in its sidewall for receiving an electrical connection to the electrode element, and the same lumen can be used for receiving the tension wire. The assembly can be sized to pass through an endoscope.
In another aspect, the invention features an assembly for taking a biopsy sample from a site within the body of a patient. The assembly includes a resecting device including forceps near its distal end for resecting and containing a tissue sample, and a sheath exterior to the resecting device and sized to be present within the body with the resecting device. The sheath includes a lumen sized to slidably receive the resecting device and an electrode element electrically isolated from the resecting device and disposed on the sheath""s outer surface for cauterizing tissue. The resecting device and the sheath are cooperatively constructed to permit sequential resecting of a tissue sample from a resecting site and cauterizing of the site with the forceps spaced from the electrode element sufficiently to avoid heat damage to the sample.
In another aspect, the invention features an assembly for taking a biopsy sample from a site within the body of a patient. The assembly includes a resecting device including forceps near its distal end for resecting and containing a tissue sample, and a sheath exterior to the resecting device and sized to be present within the body with the resecting device. The sheath and the resecting device are constructed as a unitary device and the forceps extend distally of the termination of the sheath. The sheath includes an electrode element electrically isolated from the resecting device, spaced proximally to the forceps, and disposed on the sheath""s outer surface for cauterizing tissue. The resecting device and the sheath are cooperatively constructed to permit sequential resecting of a tissue sample from a resecting site and cauterizing of the site with the forceps spaced from the electrode element sufficiently to avoid heat damage to the sample.
In another aspect, the invention features a method for taking a biopsy sample with an assembly from a site within the body of a patient. The assembly includes a resecting device having a cutter near its distal end for resecting and containing a tissue sample and a sheath exterior to the resecting device and sized to be present within the body with the resecting device. The sheath includes an electrode element electrically isolated from the resecting device and disposed on the sheath""s outer surface for cauterizing tissue. The resecting device and the sheath cooperate to permit sequential resecting of a tissue sample from a resecting site and cauterizing of the site with the cutter sufficiently spaced from the electrode element to avoid heat damage to the tissue sample. The method further includes resecting a tissue sample from a resecting site with the resecting device and containing the tissue sample with the cutter. Additionally, the electrode element is located at the resecting site with the cutter containing the sample spaced from the electrode element, and the site is cauterized by application of power to the electrode element.
Implementations of the invention may include the following features. The sheath may include a lumen sized to slidably receive the resecting device, and the method may further include inserting the resecting device within the lumen of the sheath, extending the resecting device from a distal end of the sheath to position the resecting device at a resecting site, and withdrawing the resecting device within the lumen a distance away from the distal end of the sheath. The method may include extending the cutter from the sheath to space the cutter from the electrode. The method may also include withdrawing the resecting device completely from the sheath, removing the tissue sample from the resecting device, reinserting the resecting device within the lumen of the sheath, extending the resecting device from the distal end of the sheath to position the resecting device at a new resecting site, resecting a tissue sample from the new resecting site with the resecting device, containing the tissue sample with the cutter, withdrawing the resecting device within the lumen a distance away from the electrode element, positioning electrode element at new resecting site, and cauterizing the new resecting site by application of power to the electrode element. The method may also include inserting an endoscope within the body and inserting the sheath within the endoscope. Moreover, the sheath and the resecting device may be constructed as a unitary device where the cutter extends distally of the termination of the sheath and the electrode is spaced proximally of the cutter, and the method may further include positioning the resecting device and the sheath along a treatment path, positioning the resecting device at a resecting site, resecting a tissue sample from the resecting site with the resecting device, containing the tissue sample with the cutter, positioning the electrodes at the resecting site, and cauterizing the site by application of power to the electrode element.
Embodiments may include one or more of the following advantages: For example, polyps and other aberrant tissue can be resected and the resection site can be cauterized without heat-damaging the sample or removing the sampling device from the patient""s body before cauterizing. For example, in embodiments, the resected tissue is slid axially a predetermined short distance away from the cauterizing electrodes so that heat from the electrodes does not affect the sample integrity. The bleeding of the resecting site is quickly electro-cauterized. The resection can be carried out using a cauterizing sheath having electro-cautery electrodes disposed on a distal end of the sheath and having surgical forceps slidably disposed within a lumen in the sheath. The surgical forceps are used to resect the tissue sample and axially remove the sample from the resecting site, while the electro-cautery electrodes are used to cauterize the resecting site to stop bleeding. In other embodiments, the distance between the electrodes and the forceps is fitted at a preselected spacing sufficient to avoid heat damage when the assembly is maneuvered to position the electrodes at the resection site for cauterization. The need for additional tissue removal, additional biopsy procedures, complications from blood loss, time in surgery, and patient trauma may all be reduced. The instrument can be constructed for use with a variety of existing surgical devices and can be easily manufactured.
In each of these embodiments of the invention the electrode element may reside on the outer sheath of the assembly, the distal end of the assembly or both. Various configurations of electrode elements are possible including parallel horizontal configuration or an alternating spiral configuration. In addition, electrode elements may include a three dimensional configuration to aid in cauterization.
Additional advantages and features are apparent from the following.